Ambiguity tolerance as a mediator: how mindfulness intervention enhances English reading comprehension among university students

This longitudinal study investigated whether ambiguity tolerance mediates the relationship between mindfulness intervention and second language (L2) English reading comprehension among Chinese university students learning English as a foreign language (EFL). Using a single-site randomized controlled design with stratified allocation, 160 participants were randomly assigned to either an 8-week mindfulness intervention or a no-intervention control group, with assessments at four time points: baseline (T0), mid-intervention (T1), post-intervention (T2), and three-month follow-up (T3). A latent growth curve mediation model indicated that changes in ambiguity tolerance statistically mediated the association between mindfulness training and reading comprehension improvements (indirect effect = 0.27, 95% CI [0.18, 0.36], p < 0.001), accounting for approximately 64% of the total effect. Mediation was particularly pronounced for ambiguity processing capacity and inferential ability. The mindfulness intervention was associated with substantial gains in ambiguity tolerance (d = 1.59) and in each reading comprehension dimension (d = 0.92–1.73, all ps < 0.001), and cross-lagged panel analysis showed that prior changes in ambiguity tolerance predicted subsequent reading comprehension change, whereas the reverse path was not significant. These findings are consistent with a model in which mindfulness practice enhances L2 reading comprehension, at least in part, by increasing learners’ capacity to tolerate and process textual ambiguity. Because the study was conducted at a single university without an active control condition or blinded outcome assessment, the causal interpretation should be regarded as preliminary and in need of replication in more diverse settings.